<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
        div{
            width: 200px;
            height: 200px;
            background: hsla(360, 50%, 50%,0.5)
        }
    </style>
</head>
<body>
    <div></div>
</body>
</html>
<!-- 
    Hsl 
        - hue           色调    0-360
        - saturation    饱和度  0.0%-100.0%
        - lightness     亮度 0.0%-100.0%
        - alpha         透明 0-1
    Hsla
 -->